Bioinsecticidal activity and efficacy of nanoemulsified Artemisia Campestris essential oil against Tribolium castaneum (Herbst, 1797) (Coleoptera: Tenebrionidae)

This study assessed the bioinsecticidal activity of Artemisia campestris L. essential oil (EO) in both free and nanoemulsified forms. The EO, obtained via hydrodistillation, was analyzed using GC/EIMS and found to contain high levels of monoterpene hydrocarbons, particularly α-pinene (21.0%), myrcene (14.7%), and (Z)-β-ocimene (12.7%). Bioassays targeting Tribolium castaneum evaluated antifeedant, toxic, and repellent effects using three concentrations (0.04%, 0.2%, and 0.4%). Results indicated that both forms exhibited significant antifeedant and toxic effects, with the nanoemulsified EO (NEEO) showing higher toxicity levels, particularly 70% against larvae at 0.4%. NEEO demonstrated the lowest LC50 values across all insect stages, with 0.506% vs. 0.780% for adults, 0.281% vs. 0.728% for larvae, and 0.220% vs. 0.538% for pupae. Additionally, NEEO provided a better repellent effect against adults, achieving an inhibition ratio below 1 at all concentrations. These preliminary findings indicate that NEEO A. campestris may represent a promising eco-friendly approach for managing stored-product pests, although further investigations are needed to confirm its efficacy under different conditions.